1. Field of the Invention
The present invention relates to a deposition method, a method of manufacturing a semiconductor device, and a semiconductor device, particularly to a deposition method of a low dielectric constant insulating film using a chemical vapor deposition method, a method of manufacturing a semiconductor device, and a semiconductor device, which are provided with a low dielectric constant interlayer insulating film that is made up of a barrier insulating film coating copper wire and a low dielectric constant insulating film.
2. Description of the Prior Art
In recent years, higher data transfer speed has been required with higher integration and higher density of a semiconductor integrated circuit device. For this reason, an insulating film having a low dielectric constant with a small RC delay time (hereinafter, referred to as a low dielectric constant insulating film) has been used.
Further, in the deposition method of the low dielectric constant insulating film, N2O, O2 or H2O gas has been conventionally used as oxidizing agent in addition to silicon containing compound.
However, in the deposition using O2 gas out of N2O, O2 and H2O gas as the oxidizing agent, a formed film contains OH and it is difficult to reduce a relative dielectric constant (k) to 3.0 or less.
Since H2O has slow oxidizing rate, it requires a relatively large flow rate and a deposition rate decreases to the range of 200 nm/min.
Further, although oxidization is easily controlled in N2O, a formed film contains nitrogen (N) and there is a possibility of causing excessive crosslinking reaction of chemically amplified resist due to the following reason.
Specifically, there is the case where the chemically amplified resist for KrF or ArF is employed to expose a line width of 0.13 μm or less when via holes and wiring grooves are formed by a dual damascene method in a low dielectric constant insulating film deposited using deposition gas containing nitrogen. In this case, there has been a problem that patterns as designed could not be formed. According to various examinations, it is presumed that this phenomenon is caused by the emission of nitrogen in the low dielectric constant insulating film and the generation of excessive crosslinking reaction of resist. The phenomenon tends to occur particularly when N2O is used as the oxidizing agent of the deposition gas of the low dielectric constant insulating film.